/// <summary>
/// Read a single DXF record from an ASCII DXF file consisting of the record type and value
/// </summary>
/// <param name="rec"></param>
/// <param name="lineNumber"></param>
/// <param name="readingTextEntity"></param>
/// <returns></returns>
public bool ReadASCIIDXFRecord(out DXFRecord rec,
ref int lineNumber,
bool readingTextEntity = false)
{
rec = new DXFRecord();
var recTypeString = _aSCIIdxfFile.ReadLine();
rec.recType = Convert.ToUInt16(recTypeString);
if (_aSCIIdxfFile.EndOfStream)
{
return(false); // may be ASCII but not DXF format
}
lineNumber++;
if (rec.recType <= ASCIIDXFRecordsMax)
{
var line = _aSCIIdxfFile.ReadLine();
switch (ASCIIDXFRecordTypeLookUp[rec.recType])
{
case ASCIIDXFRecordType_Integer:
rec.i = Convert.ToInt32(line);
break;
case ASCIIDXFRecordType_Real:
rec.r = Convert.ToDouble(line);
break;
case ASCIIDXFRecordType_String:
{
rec.s = line;
// We do not want to remove leading or trailing spaces from
// the text in DXF text entities (TEXT and M TEXT). These
// group codes 1 (for TEXT) and 1&3 (for M TEXT). If the caller
// has advised it is reading a DXF text entity we no do not
// strip the spaces from the string value.
if (readingTextEntity)
{
if (rec.recType != 1 && rec.recType != 3)
{
rec.s = rec.s.Trim();
}
}
else
{
rec.s = rec.s.Trim();
}
break;
}
}
lineNumber++;
}
return(true);
}
private bool GetStartOfNextEntity(out DXFRecord rec)
{
do
{
if (!ReadDXFRecord(out rec))
{
return(false);
}
} while (rec.recType != 0);
// ReSharper disable once StringLiteralTypo
return(rec.s == "ENDSEC");
}
/// <summary>
/// Reads the next record from the DXF file
/// </summary>
/// <param name="rec"></param>
/// <returns></returns>
public bool ReadDXFRecord(out DXFRecord rec)
{
if (_reuseRecord)
{
rec = _lastRecord;
_reuseRecord = false;
return(true);
}
else
{
var result = DXFFileIsBinary ? ReadBinaryDXFRecord(out rec, ref _dxfLine) : ReadASCIIDXFRecord(out rec, ref _dxfLine);
_lastRecord = rec;
return(result);
}
}
/// <summary>
/// Locates a named section in a DXF file to begin reading records from
/// </summary>
/// <param name="name0"></param>
/// <param name="name2"></param>
/// <returns></returns>
public bool FindSection(string name0, string name2)
{
var TestString = "";
var rec = new DXFRecord();
var _haveFoundSection = false;
while (!_haveFoundSection)
{
// Scan for a section start
var foundSectionStart = false;
while (!foundSectionStart)
{
if (!ReadDXFRecord(out rec))
{
return(false);
}
if (rec.recType != 0)
{
continue;
}
TestString = rec.s.ToUpper(CultureInfo.InvariantCulture);
// ReSharper disable once StringLiteralTypo
foundSectionStart = string.Compare(TestString, name0, StringComparison.InvariantCulture) == 0 || TestString == "ENDSEC" || TestString == "SECTION";
}
// ReSharper disable once StringLiteralTypo
if (TestString != "ENDSEC") // empty section
{
if (!ReadDXFRecord(out rec))
{
return(false);
}
TestString = rec.s.ToUpper(CultureInfo.InvariantCulture);
}
_haveFoundSection = rec.recType == 2 && string.Compare(TestString, name2, StringComparison.InvariantCulture) == 0;
}
return(true);
}
/// <summary>
/// Read a DXF record from a binary DXF file
/// </summary>
/// <param name="rec"></param>
/// <param name="lineNumber"></param>
/// <param name="readingTextEntity"></param>
/// <returns></returns>
public bool ReadBinaryDXFRecord(out DXFRecord rec,
ref int lineNumber,
bool readingTextEntity = false)
{
rec = new DXFRecord();
var buffer = new byte[100];
// Read the record number
if (_dXFFileIsPostR13c3)
{
_binarydxfFile.Read(buffer, 0, 2);
rec.recType = BitConverter.ToUInt16(buffer);
}
else
{
var binaryRecType1 = _binarydxfFile.ReadByte();
if (binaryRecType1 != 255)
{
rec.recType = (ushort)binaryRecType1;
}
else // escaped record number
{
_binarydxfFile.Read(buffer, 0, 2);
rec.recType = BitConverter.ToUInt16(buffer);
}
}
if (rec.recType >= BinaryDXFRecordTypeLookUp.Length)
{
return(false);
}
switch (BinaryDXFRecordTypeLookUp[rec.recType])
{
case BinaryDXFRecordType_String:
var builder = new StringBuilder();
// read chars until we find a #0
byte theByte;
do
{
theByte = (byte)_binarydxfFile.ReadByte();
if (theByte != 0)
{
builder.Append((char)theByte);
}
} while (theByte != 0);
rec.s = builder.ToString();
// We do not want to remove leading or trailing spaces from
// the text in DXF text entities (TEXT and MTEXT). These
// group codes 1 (for TEXT) and 1&3 (for MTEXT). If the caller
// has advised it is reading a DXF text entity we no do not
// strip the spaces from the string value.
if (readingTextEntity)
{
if (!(rec.recType == 1 || rec.recType == 3))
{
rec.s = rec.s.Trim();
}
}
else
{
rec.s = rec.s.Trim();
}
break;
case BinaryDXFRecordType_Real:
_binarydxfFile.Read(buffer, 0, 8);
rec.r = BitConverter.ToDouble(buffer);
break;
case BinaryDXFRecordType_Integer1:
_binarydxfFile.Read(buffer, 0, 1);
rec.i = buffer[0];
break;
case BinaryDXFRecordType_Integer2:
_binarydxfFile.Read(buffer, 0, 2);
rec.i = BitConverter.ToInt16(buffer);
break;
case BinaryDXFRecordType_Integer4:
_binarydxfFile.Read(buffer, 0, 4);
rec.i = BitConverter.ToInt32(buffer);
break;
case BinaryDXFRecordType_Integer8:
_binarydxfFile.Read(buffer, 0, 4);
rec.i = BitConverter.ToUInt32(buffer);
break;
case BinaryDXFRecordType_ExtendedData:
rec.s = "";
var recLength = _binarydxfFile.ReadByte();
_binarydxfFile.Position += recLength;
break;
default:
return(false);
}
lineNumber++;
return(true);
}
